New Coastal Setbacks and Shoreline Rules Enhance Beach Protections
The importance of healthy beaches and dunes for our communities in Hawai‘i cannot be overstated. They provide a natural buffer protecting coastal development and infrastructure from erosion and coastal flooding. Sandy beaches are also important cultural resources, serve as critical wildlife habitat, improve water quality, and provide immeasurable mental and physical health benefits to our community. Yet beaches are a fragile resource that exists in a delicate balance between ocean and landward forces. It should also be stressed that the beach is a public trust resource for the enjoyment and use of the entire community, a fact that is enshrined in the Hawaiʻi State Constitution.
Already, 13 miles of sandy beaches have been lost throughout the islands and 70% of sandy beaches on O’ahu, Maui, and Kaua‘i are chronically eroding. While Surfrider Foundation continues to work towards implementing holistic solutions like a statewide managed retreat program, the local counties in Hawaiʻi have taken significant steps towards more proactive shoreline protections.
Important Terms to Know:
- Shoreline Setbacks – How close a house or structure can be built to the shoreline (affects new construction and buildings, not existing buildings). Existing buildings that fall within new shoreline setbacks become “legal nonconforming” structures.
- Shoreline Management Area (SMA) – Each island in Hawaiʻi has a coastal area designated as the “Special Management Area” or SMA. The SMA is a zone along the coastline that requires additional permitting and oversight due to its sensitive ecological nature.
In March 2023, the Maui County Planning Commission passed amendments to the County’s Special Management Area and Shoreline Rules. The amended Maui SMA rules incorporate projected sea level rise and erosion rates into the County’s shoreline setbacks and utilizes the Hawaiʻi Sea Level Rise Viewer. Previously, shoreline setbacks in Maui County were based on historic erosion rates. By incorporating projected sea level rise of 3.2 feet, the new rules provide more adequate protections of shoreline areas that are slated for development or new build. The updated rules took nearly 10-years and many revisions to pass.
In October 2022, the County of Kauaʻi became the first municipality in the nation to incorporate sea level rise projections into its county building code. The Kauaʻi Sea Level Rise Constraint District requires new residential houses to be elevated above projected flooding and high wave depths (given 3.2 feet sea level rise).
In March 2023, Honolulu Mayor Rick Blangiardi signed Bill 41 and Bill 42 that increase coastal resiliency and protections.
Ordinance 23-3 (Bill 41): Shoreline Setbacks – Unlike Maui and Kauaʻi, whose shoreline setbacks for new construction are based on historic erosion rates, setbacks on Oʻahu were only 40 feet from the shoreline. Bill 41 increased the minimum shoreline setback on Oʻahu for new construction and incorporated erosion rates into the shoreline setback formula. In most cases, the shoreline setback for Oʻahu is now 40 feet plus 70 times the average historical erosion rate for that particular section of beach (40ft + 70 x historical erosion rate). Incorporating historical erosion rates in setbacks regulations provides a larger buffer between rising seas, shoreline erosion, and built property like houses, hotels, and roads. Inadequate setbacks have led to reliance on seawalls, sandbags, and other forms of shoreline “hardening” that protects private property at the expense of the sandy shoreline.
Ordinance 23-4 (Bill 42): Special Management Area Rules Updates – Ordinance 23-4 updates the SMA rules on Oʻahu to provide additional protections against the impacts of coastal hazards. These include sea level rise and coastal erosion. The updated rules also ensure that the Oʻahu SMA rules are consistent with the State’s Coastal Zone Management regulations that were updated in 2020. Ordinance 23-4 also includes science-based planning considerations for the coastal zone of O’ahu.
We are thankful to our local Hawai’i chapters and coastal advocates who have provided testimony and support for these bills. We also recognize the important work of Sea Grant Hawai’i and The School of Ocean and Earth Science and Technology who provide the necessary data and technical information that informs these rules.